Maurizio Spurio Department of Physics and INFN – Bologna 1 M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

2 among the most intriguing science questions: origin of cosmic rays  eV ? astrophysical acceleration mechanism ? origin of relativistic jets ? dark matter ? exotics Cosmic sources of neutrinos Extragalactic: Active Galactic Nuclei, GRBs Galactic: micro quasars, supernova remnants … neutrinos reach Earth undisturbed: need large detector and good angular resolution HESS TeV  rays (p+X   0   ) at the centre of our galaxy from supernova remnant RX J Expect: p+X     p n  Ref: EPJC 65 (2010) 649, arXiv: v2

M.Spurio- The ANTARES Neutrino Telescope ICHEP Mkn 501 Mkn 421 CRAB SS433 Mkn 501 RX J GX339-4 SS433 CRAB VELA Galactic Centre AMANDA / IceCube (South Pole) ANTARES (43 o N) 1.5  sr common view over a day acceptance visible sky

 CPPM, Marseille  DSM/IRFU/CEA, Saclay  APC, Paris  LPC, Clermont-Ferrand  IPHC (IReS), Strasbourg  Univ. de H.-A., Mulhouse  IFREMER, Toulon/Brest  C.O.M. Marseille  LAM, Marseille  GeoAzur Villefranche IFIC, Valencia UPV, Valencia UPC, Barcelona  NIKHEF (Amsterdam)  KVI (Groningen)  NIOZ Texel  University of Erlangen  Bamberg Observatory ISS, Bucarest  ITEP, Moscow  Moscow State Univ 7 COUNTRIES 28 INSTITUTES ~ 150 SCIENTISTS AND ENGINEERS  University/INFN of Bari  University/INFN of Bologna  University/INFN of Catania  LNS – Catania  University/INFN of Pisa  University/INFN of Rome  University/INFN of Genova 4 M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

m ~60-75 m buoy 350 m 100 m Junction box readout cables 45 km electro- optical cable storey 12 detection lines 25 storeys/line 3x10” PMT/storey 885 PMT s

M.Spurio- The ANTARES Neutrino Telescope ICHEP Two kinds of background : 1. (Particle) Physics Background : cosmic rays (atmospheric  and ). 2. Optical Background: bioluminescence and 40 K decay (sea environment): Continuous 40 K (~30kHz) and bioluminescence (~40 kHz, long term average). Bursts from bioluminescence (~MHz). Two kinds of background : 1. (Particle) Physics Background : cosmic rays (atmospheric  and ). 2. Optical Background: bioluminescence and 40 K decay (sea environment): Continuous 40 K (~30kHz) and bioluminescence (~40 kHz, long term average). Bursts from bioluminescence (~MHz). ANTARES 5 Lines Full ANTARES

M.Spurio- The ANTARES Neutrino Telescope ICHEP Ref: arXiv Fast tracking: almost online to discriminate atmospheric muons /neutrinos; No detailed calibration/ no real time detector positioning needed Angular resolution:  3 o. Used in most analyses in this talk. The precise tracking: detailed real-time positioning of the detector; detailed PMTs charge/time calibration; detailed systematic knowledge of the apparatus (OMs angular acceptance, etc.) Angular resolution: up to  0.2 o. Used in the diffuse analysis search

M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010 height time 8 reconstruction of muon trajectory from time, charge and position of PMT hits assuming relativistic muon emitting Cherenkov light Fast tracking

M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010 Example of a reconstructed up-going muon (i.e. a neutrino candidate) detected in 6/12 detector lines: time height 9 Fast tracking

M.Spurio- The ANTARES Neutrino Telescope ICHEP

M.Spurio- The ANTARES Neutrino Telescope ICHEP Ref: arXiv: , Accepted to APP Dots: Data  MUPAGE Monte Carlo. [Com. Phys. Comm. 179(2009)915]  CORSIKA + QGSJET + NSU (model of the primary CR)  CORSIKA + SIBYLL + NSU  CORSIKA + QGSJET + “poly- gonato” model. Shadowed band: systematic uncertainty w.r.t. black line. Zenith angle distribution of reconstructed tracks from atmospheric  ’s  5 line detector. Fast tracking Main sources of syst. uncertainties: environmental parameters (absorption and scattering) detector parameters (OM efficiency) (physics) hadronic interaction models (physics) models of cosmic ray composition

M.Spurio- The ANTARES Neutrino Telescope ICHEP Fast tracking

M.Spurio- The ANTARES Neutrino Telescope ICHEP line data (May-Dec. 2007) line data (2008)= 341 days detector live time Upgoing: 1062 neutrino candidates: 3.1 ν candidates/day Monte Carlo: atmospheric neutrinos: 916 (30% syst. error) Wrong reco atmospheric  : 40 (50% syst. error) Fast tracking Zenith angle

M.Spurio- The ANTARES Neutrino Telescope ICHEP Fast tracking

M.Spurio- The ANTARES Neutrino Telescope ICHEP list of 25 potential sources (stringent cuts to reduce background) Analysis optimization based on simulations no excess found after 5-line data unblinding 140 days of detector livetime Fast tracking

M.Spurio- The ANTARES Neutrino Telescope ICHEP  direct photons +  scattered photons + light from EM showers Energy estimator= Repetition (R) of integration gate on the same Optical Module

M.Spurio- The ANTARES Neutrino Telescope ICHEP Precise tracking Wrongly reconstructed Well reconstructed

M.Spurio- The ANTARES Neutrino Telescope ICHEP Rejection of downward going atmospheric muons (using measured zenith angle, track quality parameter, number of hits) 2.Separation of the atmospheric background from signal using the energy estimator R 3.Blind analysis. Model Rejection Factor [APP 19 (2003)393] to select the best cut value on R (=1.31) predefined from MC only.

M.Spurio- The ANTARES Neutrino Telescope ICHEP R< 1.31 Bartol (conventional ) Max “prompt” model 2.1 Data 125 R  1.31 Atmospheric 10.7  2 Data 9 Precise tracking

M.Spurio- The ANTARES Neutrino Telescope ICHEP E 2  (E) 90% = 4.7×10 -8 GeV cm -2 s -1 sr TeV<E<2.5 PeV

M.Spurio- The ANTARES Neutrino Telescope ICHEP Log 10 (E  [GeV]) E 2   [GeV cm -2 s -1 sr -1 ] <1 : model rejected

M.Spurio- The ANTARES Neutrino Telescope ICHEP Receive GRB alerts from Satellites (Fermi, Swift...) search for coincident neutrinos within time window (~100 s) Send neutrino cluster alert for optical follow-up Trigger: multiple / HE single neutrino event; Reconstruction “on-line” (<10ms) Alert message to Tarot Telescope in La Silla (Chile). Tarot takes 6 images of 3 minutes immediately and after 1, 3, 9 and 27 days sending alerts to the ROTSE system (4 telescopes) Correlation with AUGER source distribution investigate directional correlation of neutrinos and UHE particles Correlation with VIRGO-LIGO signals investigate correlation of neutrinos and gravitational waves

M.Spurio- The ANTARES Neutrino Telescope ICHEP ANTARES continuously taking data complements the sky coverage of IceCube has a broad physics program determined most sensitive upper limit on diffuse flux paves the way for KM3NeT

M.Spurio- The ANTARES Neutrino Telescope ICHEP

25 angular resolution < 0.2° above  10 TeV limited tracking accuracy due to time resolution:  Light scattering  ~ 1.0 ns  TTS in PMT  ~ 1.3 ns  ti me calibration  < 0.5 ns  OM position  < 10 cm (↔  < 0.5 ns) dominated by reconstruction   rec −  gener.  rec − gener. dominated by kinematics angular resolution = difference between reconstructed and MC generated angles vs. neutrino energy M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

Transceivers on the bottom of each line 5 hydrophones at specific heights on each line 4 autonomous transponders around the apparatus Sound velocimeters installed at various depths Tiltmeter and compass at each storey Measurements performed every 2 minutes 20 days resolution better than 10 cm Position of hydrophone relative to line base location 26 M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

3 OMs Optical LED beacon - Electronics + calibration   ~ 0.5 ns - TTS in photomultipliers   ~ 1.3 ns - Light scattering + dispersion in sea water   ~ 1.5 ns at 40 m Angular resolution  0.3 o (for E > 10 TeV ) Including the acoustic position resolution and the -µ angle Time difference between the LED OB and an OM  = 0.4 ns 27 M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

The biggest challenge is to determine the separate contribution of absorption and scattering 28 M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

  PMT Has to be known to compute reconstruction efficiencies and effective areas Detailed GEANT4 simulation of the OM LED Measurements were performed in a water tank Photon scattering affects the measurements angular acceptance determination is not reliable at large  PMT Dedicated measurements of the photocathode surface of OMs  Angular acceptance uncertainty at large  affects  flux significantly, but not flux 29 M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

40 K 40 Ca  e - (  decay)  Cherenkov Gaussian peak on coincidence plot Peak offset Integral under peak = rate of correlated coincidences High precision (~5%) monitoring of OM efficiencies Cross check of time calibration No dependence on bioluminescent activity has been observed Heide Costantini – INFN Genova RICH2010, 3 rd May M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010

Resolution better than 10 cm Acoustic transceiver Acoustic transceiver hydrophone Hydrophone position relative to line base location (20 days) THE ANTARES DETECTOR POSITIONING SYSTEM 31 REAL TIME POSITIONING  Acoustic positioning system + set of tiltmeters and compasses. Transceivers (RxTx) on the bottom of the lines, 4 autonomous transponders around the apparatus. 5 hydrophones (Rx) per line at specific heights. Tiltmeter and compass per storey, sound velocimeters (various depths). RECONSTRUCTION OF THE LINE SHAPE  GLOBAL  2 FIT TO LINE SHAPE MODEL (BEHAVIOUR OF LINE: SEA CURRENT) 31 M.Spurio- The ANTARES Neutrino Telescope ICHEP 2010